n2doc

n2doc's Journal

December 1, 2017

After 37 years, Voyager 1 has fired up its trajectory thrusters

At present, the Voyager 1 spacecraft is 21 billion kilometers from Earth, or about 141 times the distance between the Earth and Sun. It has, in fact, moved beyond our Solar System into interstellar space. However, we can still communicate with Voyager across that distance.

This week, the scientists and engineers on the Voyager team did something very special. They commanded the spacecraft to fire a set of four trajectory thrusters for the first time in 37 years to determine their ability to orient the spacecraft using 10-millisecond pulses.

After sending the commands on Tuesday, it took 19 hours and 35 minutes for the signal to reach Voyager. Then, the Earth-bound spacecraft team had to wait another 19 hours and 35 minutes to see if the spacecraft responded. It did. After nearly four decades of dormancy, the Aerojet Rocketdyne manufactured thrusters fired perfectly.

“The Voyager team got more excited each time with each milestone in the thruster test. The mood was one of relief, joy, and incredulity after witnessing these well-rested thrusters pick up the baton as if no time had passed at all,” said Todd Barber, a propulsion engineer at the Jet Propulsion Laboratory in California.

more

https://arstechnica.com/science/2017/12/after-37-years-voyager-has-fired-up-its-trajectory-thrusters/

They built those things well, didn’t they?

December 1, 2017

Melania's Demonic Holiday Decorations, Explained

by Kendra Wells

https://thenib.com/melania-s-demonic-holiday-decorations-explained?t=recent

December 1, 2017

How Professionals Wrestle With One of the Worlds Scariest Plants

If you happened to be driving past Cootes Paradise Sanctuary in Hamilton, Ontario, on a particular mid-July day in 2016, you might have seen something that left you scratching your head: three figures in head-to-toe hazmat suits and safety goggles, two of them holding shovels and the other toting a human-sized object wrapped in garbage bags, all waiting to cross the four-lane road and get back to their parked truck.

“There were a whole bunch of cars coming by at the time,” recalls Nadia Cavallin, who led the team. “People were slowing down and looking at us with their mouths wide open.”

Despite appearances, Cavallin—the herbarium curator at the Royal Botanical Gardens, of which Cootes Paradise Sanctuary is a part—wasn’t the dangerous organism in this scenario. That honor goes to the thing in the garbage bags: a six-foot giant hogweed, or Heracleum mantegazzianum.

An invasive plant that can grow up to 14 feet tall, the sap of the giant hogweed can cause second-degree burns (thus the hazmat suits) and, potentially, blindness (thus the safety glasses). Plus, it’s sneaky, resembling a number of less harmful plants. By wrestling that specimen out of the ground and back to the lab, Cavallin and her colleagues were risking their skins to educate the public.

more
https://www.atlasobscura.com/articles/giant-hogweed-sap-burn-dangerous

And some music!